Low and High Surface Brightness Galaxies at Void Walls

TL;DR

This study investigates how the distribution of low and high surface brightness galaxies varies at void walls in the universe, revealing that blue, star-forming LSBGs decrease while HSBGs increase, suggesting environmental influence on galaxy evolution.

Contribution

It provides the first analysis of LSBG and HSBG fractions at void walls in SDSS data, controlling for local density, and links galaxy properties to large-scale environment effects.

Findings

Significant decrease in blue, star-forming LSBGs at void walls.

Corresponding increase in blue, star-forming HSBGs at void walls.

Negligible change in red LSBGs and HSBGs across environments.

Abstract

We study the relative fraction of low and high surface brightness galaxies (LSBGs and HSBGs) at void walls in the SDSS DR7. We focus on galaxies in equal local density environments. We assume that the host dark-matter halo mass (for which we use SDSS group masses) is a good indicator of local density. This analysis allows to examine the behavior of the abundance of LSBG and HSBG galaxies at a fixed local density and distinguish the large-scale environment defined by the void geometry. We compare galaxies in the field, and in the void walls; the latter are defined as the volume of void shells of radius equal to that of the void. We find a significant decrement, a factor $\sim 4$, of the relative fraction of blue, active star-forming LSBGs in equal mass groups at the void walls and the field. This decrement is consistent with an increase of the fraction of blue, active star-forming HSBGs. By contrast, red LSBGs and HSBGs show negligible changes. We argue that these results are consistent with a scenario where LSBGs with blue colors and strong star formation activity at the void walls are fueled by gas from the expanding void regions. This process could lead to LSBG to HSBG transformations.